如何在Java Swing的JFrame中设置光标位置？

1. 强制限制光标在窗口范围内 #

不用退出程序，直接把光标锁定在JFrame内，彻底避免移出窗口的报错问题。通过MouseMotionListener监听鼠标移动，结合Robot类强制拉回超出边界的光标：

import java.awt.*;
import java.awt.event.MouseMotionAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;

public class GameFrame extends JFrame {
    private Robot robot;

    public GameFrame() {
        setSize(800, 600);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setLocationRelativeTo(null);
        setVisible(true);

        try {
            robot = new Robot();
        } catch (AWTException e) {
            e.printStackTrace();
        }

        addMouseMotionListener(new MouseMotionAdapter() {
            @Override
            public void mouseMoved(MouseEvent e) {
                Rectangle winBounds = getBounds();
                int screenCursorX = e.getXOnScreen();
                int screenCursorY = e.getYOnScreen();

                int newX = screenCursorX;
                int newY = screenCursorY;
                boolean needAdjust = false;

                // 左边界
                if (screenCursorX < winBounds.x) {
                    newX = winBounds.x + 5;
                    needAdjust = true;
                }
                // 右边界
                else if (screenCursorX > winBounds.x + winBounds.width - 10) {
                    newX = winBounds.x + winBounds.width - 10;
                    needAdjust = true;
                }
                // 上边界
                if (screenCursorY < winBounds.y) {
                    newY = winBounds.y + 5;
                    needAdjust = true;
                }
                // 下边界
                else if (screenCursorY > winBounds.y + winBounds.height - 10) {
                    newY = winBounds.y + winBounds.height - 10;
                    needAdjust = true;
                }

                if (needAdjust) {
                    robot.mouseMove(newX, newY);
                }
            }
        });
    }

    public static void main(String[] args) {
        new GameFrame();
    }
}

2. 主动设置光标到指定位置 #

如果需要主动将光标移到某个位置（比如窗口中心、敌人位置），直接用Robot.mouseMove(int screenX, int screenY)方法，参数是屏幕绝对坐标：

// 示例：将光标移到窗口中心
Rectangle winBounds = getBounds();
int centerScreenX = winBounds.x + winBounds.width / 2;
int centerScreenY = winBounds.y + winBounds.height / 2;
robot.mouseMove(centerScreenX, centerScreenY);

3. 修复移出窗口报错的根源 #

你遇到的报错，本质是敌人追踪逻辑未处理光标在窗口外的情况。可以在获取光标位置后先做边界校验，用窗口边缘值替代超出的坐标：

// 获取当前光标屏幕坐标
Point cursorPos = MouseInfo.getPointerInfo().getLocation();
Rectangle winBounds = getBounds();

// 校验并修正光标位置
if (!winBounds.contains(cursorPos)) {
    cursorPos.x = Math.max(winBounds.x, Math.min(cursorPos.x, winBounds.x + winBounds.width));
    cursorPos.y = Math.max(winBounds.y, Math.min(cursorPos.y, winBounds.y + winBounds.height));
}

// 用修正后的坐标计算敌人追踪路径
// enemy.moveTowards(cursorPos);

内容的提问来源于stack exchange，提问作者Alán Dryaev